(1) Field of the Invention
The present invention relates to porous sintered bodies and solid oxide fuel cells using such porous sintered bodies as air electrodes.
(2) Related Art Statement
In developing solid oxide fuel cells (SOFC), it is important to discover materials stable at high temperatures. As a material for air electrodes of the SOFC, lanthanum manganite sintered bodies have now been considered promising (Energy General Engineering, No. 13, Vol. 2, pp 52-68, 1990). As such lanthanum manganite sintered bodies, some having almost chemically stoichiometric compositions or others having manganese-rich compositions in which no elements are present in a part of A-sites (to be occupied by lanthanum), are known. It is reported that the lanthanum manganite sintered body having the composition in which no elements are present in a part of the A-sites decreases its weight as the temperature rises from room temperature to 1000.degree. C. (J. ELectrochem. Soc. vol. 138, No. 5, pp 1519-1523, 1991). In this case, the weight of the sintered body begins to decrease from near 800.degree. C. In particular, a porous sintered body composed of lanthanum manganite doped with Ca or Sr at A-sites is considered promising as a material for air electrodes including self-supporting type air electrode tubes.